A flatbed image reading device reads an image formed (printed) on a document by means of an image pickup device in a state that the document is placed on a document placing table. In this flatbed image reading device, if a document placed on the document placing table is curved, the quality of read image data deteriorates.
In response to this disadvantage, JP-A-60-166943 describes a technique to correct the curvature of the document by pressing the document to the document placing table by a document pressing member attached on a cover which covers the document placing table.
However, in the case where one end of the document is bound (assembled) like a book or the document has high rigidity (firm), even if the document is pressed by the document pressing member, the curvature of the document could not be reliably corrected, and the quality of read image data could not be sufficiently improved.
For such a case, for example, JP-A-2003-234890 describes a technique to prevent the quality of image data from being deteriorated by correcting image data read by an image pickup device through an image data correction processing.
However, the image data correction processing is a great load processing. Therefore, the document reading speed would become lower by the correction processing and the efficiency of a document reading operation would deteriorate.